Apparatus and method for controlling transmission and reception of basic safety messages by pedestrian users

ABSTRACT

Safety message monitoring operations and/or safety message transmission operations are controlled for a mobile wireless communications device. The periodicity with regard to safety message monitoring and/or safety message transmissions is varied based on the environment of the mobile wireless device. The transmission power level with regard to safety message transmissions is varied based on the environment of the mobile wireless device. In some embodiments, safety message monitoring and transmission operations are disabled when the mobile device is determined to be inside a building or inside a vehicle. In some embodiments, safety message monitoring rate and safety message transmission rate is varied as a function of proximity to vehicular traffic and/or the level of detected vehicular traffic. In some embodiments, safety message transmission power level is varied as a function of proximity to vehicular traffic and/or the level of detected vehicular traffic.

RELATED APPLICATIONS

The present application claims the benefit of U.S. Provisional PatentApplication Ser. No. 61/590,025, filed Jan. 24, 2012, titled “METHODSAND APPARATUS TO OPERATE A CELLPHONE IN CONJUNCTION WITH A DSRC-ENABLEDVEHICLE” and claims the benefit of U.S. Provisional Patent ApplicationSer. No. 61/589,853, filed Jan. 23, 2012, titled “APPARATUS AND METHODFOR CONTROLLING TRANSMISSION AND RECEPTION OF BASIC SAFETY MESSAGES BYPEDESTRIAN USERS” both of which are assigned to the assignee of thepresent application and both of which are hereby expressly incorporatedby reference in their entirety.

FIELD

Various embodiments are directed to controlling the transmission andreception of safety messages by portable wireless communications userdevices, e.g., cell phones, laptops, and/or other handheld devices.

BACKGROUND

The 802.11p standard has been proposed for use in the 5.9 GHz spectrumfor vehicular safety and commercial use. The FCC has allocated 7channels of 10 MHz each for this purpose. It is envisioned that vehicleswill periodically broadcast safety messages to indicate their positionand velocity on the road.

The current 802.11p based DSRC wireless access in vehicular environments(WAVE) systems have a basic safety message format where vehiclesperiodically announce their position, velocity, and other attributes toother cars allowing the neighboring traffic to track the vehicles'positions and avoid collisions, improve traffic flow, etc. The standarddoes not preclude pedestrians from utilizing this spectrum andperiodically transmitting basic safety messages which can indicate thepedestrians' presence to vehicles around them. However, the spectrumallocated for safety messages is different than that normally used bycell phones for voice communications.

Typically, in vehicular systems, the basic safety messages aretransmitted and received periodically in a reserved channel, e.g., asafety channel or control channel, and the transmission periodicity canbe as high as once every 50 milliseconds. For vehicular systems, thisfrequency may not be an excessive burden on the battery or the channelresources.

However, transmitting safety messages in the spectrum allocated forsafety messages too often by a pedestrian's phone, assuming the phoneincludes a transmitter capable of using the spectrum allocated forsafety messages, can be a drain on a phone's battery. In addition, the802.11p spectrum for safety messages can become congested with little orno benefit if a large number of pedestrians' phones send out safetymessages which are of little practical use, e.g., because the pedestrianis not close to a road or traffic.

To enable receipt of safety messages communicated in the spectrumallocated for safety messages may require an 802.11p radio to beswitched on for significant durations of time and can be a burden interms of consumption of battery power. Thus, keeping the receiver on,with regard to safety message operations, in an environment where apedestrian user is not interacting with road traffic can lead to anunproductive use of battery resources.

Furthermore, a large number of pedestrian users who are not activelyusing a road may quickly congest the use of a safety channel. Forexample, the cell phones of driver and passenger of a vehicle may bothtransmit safety messages which are likely to be redundant when thevehicle in which the driver and passenger are located transmits safetymessages.

In view of the above discussion, it should be appreciated that there isa need for methods and apparatus for controlling whether and/or when adevice will transmit safety messages. It should be appreciated that itwould be desirable if at least some methods and/or apparatus reducedand/or avoided the transmission of safety messages that are not likelyto be useful and/or which provide redundant or similar information.

SUMMARY

Various embodiments relate to controlling the transmissions and/orreception of safety messages, e.g., dedicated short range communications(DSRC) safety messages, by portable wireless terminals, e.g., handheldor man portable wireless communications devices. Some features ofvarious embodiments relate to methods and apparatus which can be used tocontrol the operations of a cell phone or other portable wirelesscommunications device when it operates within a vehicle enabled with aDSRC radio, e.g., an 802.11p radio.

Man portable wireless communications devices, e.g., cellphone devices,may and in some embodiments do transmit vehicular safety messages usedto facilitate pedestrian and/or vehicle safety. For example, pedestriansusing the road may use their cellphone devices to transmit theirposition and movement to vehicles/other pedestrians devices in theneighborhood so that the vehicles may avoid the pedestrian users and/orpedestrians can have an idea of congestion and/or other informationuseful in determining a safe and fast route.

In accordance with various embodiments, transmission and/or receptionrates of messages from man portable devices, e.g., cell phones and/orother user equipment devices, is controlled based on locationinformation and/or one or more received signals. In some embodiments,the rate of monitoring for and transmitting safety message is controlledto be lower than the rate used for vehicles thereby allowing forconservation of battery power, limiting congestion of airlink resourcesand also avoiding excessive loading on the processing resources of aportable device being used.

In one embodiment, the power and periodicity of a wireless device foruse by a pedestrian are controlled with regard to safety messages. Thepower and periodicity may be varied according to the environment of thewireless device. In one embodiment, the position of the wireless devicemay, and sometimes is, used to adjust the power and/or periodicity ofsafety messages sent by the wireless device. In another embodiment,inertial measurements are used to predict the position of the pedestrianand adjust power and periodicity accordingly. In yet another embodiment,basic safety messages are monitored and the power and/or periodicity ofmessages sent by the wireless device are adjusted. In some embodiments,a basic safety message can be requested or polled by other devices.Various embodiments, may, and some do, combine and use the abovedescribed power and/or transmission control features, but allembodiments, need not include all the discussed features.

One particular exemplary embodiment is directed to a cell phone device,that can identify that it is within a building and which shuts off itsDSRC safety messages for the duration that it detects it is within thebuilding. Various methods of detecting whether the cellphone is within abuilding include: receiving a building audio identification signal,detecting a signal exceeding a predetermined receive power level from abase station transmitter known to be located within a building,determining a GPS position known to be within a building based onreceived GPS signals, determining a position known to be within abuilding based on inertial guidance information, and determiningposition based on detected RF signals and a RF fingerprint predicationmap corresponding to a building.

Another particular exemplary embodiment is directed to a cell phonedevice, that can identify that it is within a moving vehicle, e.g., amoving car. In some embodiments, the cell phone device, which hasdetected that it is in a moving vehicle with DSRC capability, shuts offits DSRC safety messages for the duration that it detects it is withinthe moving vehicle. Various methods of detecting whether the cellphoneis within a moving vehicle, e.g., a moving car, are described including:receiving signals from a vehicle's, e.g., car's, audio system, detectingvelocity consistent with vehicular motion, and/or detecting a radiosignal or signals, e.g., safety messages, from a vehicle's, e.g., car's,DSRC system.

An exemplary method of operating a communications device, in accordancewith some embodiments, includes generating device location informationbased on at least one of a received signal or inertial guidanceinformation and controlling at least one of a safety message monitoringoperation or safety message transmission operation based on thegenerated device location information. An exemplary communicationsdevice, in accordance with some embodiments, includes at least oneprocessor configured to: (i) generate device location information basedon at least one of a received signal or inertial guidance information;and (ii) control at least one of a safety message monitoring operationor safety message transmission operation based on the generated devicelocation information. The exemplary communications device furtherincludes memory coupled to said at least one processor.

While various embodiments have been discussed in the summary above, itshould be appreciated that not necessarily all embodiments include thesame features and some of the features described above are not necessarybut can be desirable in some embodiments. Numerous additional features,embodiments, and benefits of various embodiments are discussed in thedetailed description which follows.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a drawing of an exemplary system supporting safety messagesignaling in accordance with various exemplary embodiments.

FIG. 2 is a flowchart of an exemplary method of operating acommunications device, e.g., a mobile wireless communications devicesupporting safety message signaling, in accordance with variousexemplary embodiments.

FIG. 3 is a drawing of an exemplary communications device, e.g., amobile wireless communications device, in accordance with an exemplaryembodiment.

FIG. 4 illustrates an assembly of modules which can, and in someembodiments is, used in the exemplary communications device illustratedin FIG. 3.

FIG. 5 is a flowchart of an exemplary method of operating acommunications device, e.g., a network server or base station whichcontrols a plurality mobile wireless communications devices with regardto safety message signaling, in accordance with various exemplaryembodiments.

FIG. 6 is a drawing of an exemplary communications device, e.g., anetwork server or base station, in accordance with an exemplaryembodiment.

FIG. 7 illustrates an assembly of modules which can, and in someembodiments is, used in the exemplary communications device illustratedin FIG. 6.

DETAILED DESCRIPTION

FIG. 1 is a drawing of an exemplary system 100 supporting thecommunications of safety messages, e.g. DSRC safety messages, inaccordance with various exemplary embodiments. Exemplary system 100includes a building 102 including a plurality of base stations (basestation 1 104, . . . , base station N 106) and an acoustic buildingtransmitter 108. The base stations (104, . . . , 106) transmit signalsincluding RF reference signals (103, . . . , 105), respectively, whichmay be, and sometimes are, used for mobile device position determinationwithin building 102, e.g., in accordance with a RF fingerprint map.Acoustic building transmitter 108 transmits acoustic signal 107 whichmay be, and sometimes is, used by detecting mobile communicationsdevices to recognize that the detecting mobile device is currentlylocated in building 102. In some embodiments, multiple acoustictransmitters are situated at different locations in the buildingfacilitating ranging determination within the building by a mobilewireless communications device. System 100 further includes a pluralityof cellular base stations (cellular base station 1 126, . . . , cellularbase station N 128). The cellular base stations (126, . . . , 128)transmits signals including reference signals (111, . . . , 113),respectively, which may be, and sometimes are, used for mobile deviceposition determination. In some embodiments, system 100 includes aserver node 130, e.g., a safety message control node. In someembodiments, in which mobile wireless communications devices' positionsare tracked using a centralized approach, system 100 includes mobilenode (MN) location determination server 109. The various nodes (104, . .. , 106, 126, . . . , 128, 130, 109) are coupled to a backhaul network132 over which the various devices may exchange data and information.

System 100 further includes a plurality of GPS satellites (GPS satellite1 118, . . . , GPS satellite N 120) which transmit GPS signals (122, . .. , 124) respectively. The GPS signals (122, . . . , 124) may be, andsometimes are, received by devices with GPS receivers and used todetermine time, device position, device velocity, device altitude,and/or device heading.

Exemplary system 100 also includes a plurality of roads (road A 144, . .. , road B 146), a smart traffic light 186 at an intersection, and atrain track 192. There are a plurality of motor vehicles on the roadsincluding vehicle 1 148, vehicle 2 158, and vehicle N 168). Each of thevehicles (148, 158, . . . , 168) includes a wireless communicationsmodule (150, 160, . . . , 170), respectively which supports thetransmission and reception of safety messages. Wireless communicationsmodules (150, 160, . . . , 170) transmit safety messages (156, 166, . .. , 176), respectively. Each of the vehicles (148, 158, . . . , 168)includes a GPS receiver module (154, 164, . . . , 174), respectivelywhich supports the reception of GPS signals from GPS satellites. Each ofthe vehicles (148, 158, . . . , 168) includes an acoustic transmittermodule (152, 162, . . . , 172), respectively which transmits an acousticsignal (117, 119, . . . , 121), respectively. An acoustic signal (117,119, . . . , 121) transmitted by transmitter module (152, 162, . . .172), respectively, can be, and sometimes is, used by a mobile wirelesscommunications device situated inside the vehicle (148, 158, . . . ,168), respectively to recognize that the detecting mobile wirelesscommunications device is within the vehicle (148, 158, . . . , 168),respectively. In some embodiments, acoustic signals are transmitted frommultiple speakers within a vehicle facilitating and a mobilecommunications device receiving the acoustic signals performs a rangedetermination and determines whether or not the mobile communicationsdevice is located within the vehicle.

Smart traffic light 186 includes a wireless communications module 188which supports the transmission and reception of safety messages. Train194 includes a wireless communications module 199 which supports thetransmission and reception of safety messages. Wireless communicationsmodule 199 transmits safety messages 197. Train 194 also includes a GPSreceiver module 196 which supports the reception of GPS signals from GPSsatellites. Train 194 further includes an acoustic transmitter module198 which transmits an acoustic signal 123. An acoustic signal 123transmitted by transmitter module 198 can be, and sometimes is, used bya mobile wireless communications device situated inside train 194 torecognize that the detecting mobile wireless communications device iswithin train 194.

System 100 also includes a plurality of portable mobile wirelesscommunications devices (mobile node 1 136, mobile node 2 112, mobilenode 3 193, mobile node 4 180, . . . , mobile node N 183), which areheld by operators (operator 1 134, operator 2 110, operator 3 195,operator 4 178, . . . , operator N 185), respectively. Each of themobile wireless communications devices (136, 112, 193, 180, . . . , 183)supports the reception and transmission of safety messages via itswireless communications module (138, 114, 191, 182, . . . , 177),respectively. Each of the mobile wireless communications devices (136,112, 193, 180, . . . , 183) supports the reception of GPS signals viaits GPS receiver module (140, 116, 189, 184 . . . , 179), respectively.Each of the mobile wireless communications devices (136, 112, 193, 180,. . . , 183) includes a microphone and acoustic interface module (135,137, 139, 141, . . . , 143), respectively, which supports the capabilityto receive acoustic signals and identify that the mobile wirelesscommunications device is within a building or vehicle or within aparticular building or particular vehicle. Each of the mobile wirelesscommunications devices (136, 112, 193, 180, . . . , 183) also includesan inertial guidance module including gyroscopes and accelerometers(125, 127, 129, 131, . . . , 133), respectively, which is used fordetermining position, velocity, and heading, aiding GPS, filling in foroutages of GPS, and for measuring a velocity and acceleration. In someembodiments, measurements of velocity and acceleration are used toidentify that a mobile wireless communications device is inside a movingvehicle.

In some embodiments, the rate at which safety messages are transmittedby mobile wireless communications devices of individuals isintentionally controlled to be less than the rate at which safetymessages are transmitted by vehicles.

Consider one exemplary embodiment in which mobile wirelesscommunications devices generate device location information and controlsafety message monitoring and/or safety message transmission based onthe generated device location information. Operator 1 134 with MN 1 136is not within a building or a vehicle. MN 1 136 is currently situatedrelatively far away from the roads and train track. MN 1 136 determinesits position based on one or more of: received GPS signals (122, . . . ,124), received signals (111, . . . , 113) from cellular base stations(126, . . . , 128), respectively, and inertial measurement informationfrom inertial module 125. MN 1 136 determines that it is outside avehicle and not in a building. MN 1 136 monitors safety messages fromvehicles, e.g., in terms of number of messages received, signal strengthlevel of received safety messages, number of safety messages received ina given time interval, number of different vehicles from which safetymessages were received from, number of different vehicles from whichsafety messages are received in a given time interval, and/or percentageof monitoring time during which safety messages were received, todetermine a level of vehicle activity in its region. In this example, MN1 136 decides to transmit its safety messages 142 at a relatively lowrate and a relatively low transmission power level. MN 1 136 alsodecides to monitor for safety messages at a relatively low rate.

Continuing with the example, operator 2 110 with MN 2 112 is within abuilding. MN 2 112 determines that it is in building 102 based on one ormore of: received acoustic signal 107, signals (103, . . . , 105)received from base stations (104, . . . , 106), respectively, receivedGPS signals (122, . . . , 124), and inertial measurement informationfrom inertial module 127. MN 2 112 decides to refrain from receiving andtransmitting safety messages while it is within the building.

Continuing with the example, operator 3 195 with MN 3 193 is not withina building or a vehicle. MN 3 193 is currently situated relatively closeto the road A 144. MN 3 193 determines its position based on one or moreof: received GPS signals (122, . . . , 124), received signals (111, . .. , 113) from cellular base stations (126, . . . , 128), respectively,and inertial measurement information from inertial module 129. MN 3 193determines that it is outside a vehicle and not in a building. MN 3 193monitors safety messages from vehicles, e.g., in terms of number ofmessages received, signal strength level of received safety messages,number of safety messages received in a given time interval, number ofdifferent vehicles from which safety messages were received from, numberof different vehicles from which safety messages are received in a giventime interval, and/or percentage of monitoring time during which safetymessages were received, to determine a level of vehicle activity in itsregion, and determines that the level of activity is relatively high. Inthis example, MN 3 193 decides to transmit its safety messages 187 at arelatively high rate and a relatively high transmission power level. MN3 193 also decides to monitor for safety messages at a relatively highrate.

Continuing with the example, operator 4 178 with MN 4 180 is locatedwithin moving vehicle 168. MN 4 180 determines that it is within vehicle168 and that the vehicle is moving based on one or more of: receivedacoustic signal 121, received safety messages 176 transmitted by vehicle168, received GPS signals (122, . . . , 124) and information obtainedfrom its inertial module 131. MN 4 decides to refrain from transmittingsafety messages while it is in vehicle 168. MN 4 decides to monitor forsafety messages at a relatively low rate while it is in vehicle 168.

Continuing with the example, operator N 185 with MN N 183 is locatedclose to the intersection between road A 144 and road B 146, and wouldlike to cross from one side of road A to the other side of road A.Operator N 185 selects a push to cross button on MN N 183 resulting inthe generation and transmission of safety message 181. The safetymessage 181 is received by module 188 of smart traffic light 186 whichalters, e.g., shortens, the time between light transitions at trafficlight 186. Safety messages 190 may include a message indicating the timeremaining before a light transition occurs.

It should be appreciated that the mobile wireless communications devices(136, 112, 193, 180, . . . , 183) may move throughout system 100 and anindividual wireless communications device may alter its status withregard to whether or not it is monitoring for safety messages, safetymessage monitoring periodicity, percentage of time monitoring for safetymessages, whether or not it is transmitting safety messages, safetymessage transmission periodicity, and/or safety message transmissionpower level, as a function of its detected environment. For example,consider that MN 1 136, as shown in FIG. 1 is transmitting safetymessages at a low rate and low power level and is monitoring for safetymessages at a low rate. Consider that MN 1 136 moves inside building102, and ceases monitoring for and transmitting safety messages whileinside building 102. Further consider that MN 1 136 leaves building 102and returns to transmitting safety messages at a low power level andmonitoring for safety messages at a low rate. Further consider as MN 1136 approaches the ongoing traffic, MN 1 136 increases its safetymessage transmission power level and rate and increases its safetymessage monitoring rate. Further consider that MN 1 136 enters a vehicleand detects that the vehicle is moving; and in response ceases itssafety message monitoring and safety message transmission since thevehicle has its own safety message signaling capability.

Consider another exemplary embodiment in which a network node, e.g.,server node 130 which is a safety message control node, generates devicelocation information for mobile wireless communications devices andcontrols safety message monitoring and/or safety message transmissionsof the mobile wireless communications devices based on the generateddevice location information. Thus, in one embodiment, server node 130controls safety message monitoring and/or safety message transmissionfor MN 1 136, MN 2 112, MN 3 193, MN 4 180, and MN N 183. Server node130 collects information pertaining to the MNs and vehicles in thesystem, e.g., MN location, vehicle location, information used to deriveMN location, information used to derive vehicle location, MNself-determinations as to whether or not it is in a building, MNself-determinations as to whether or not it is in a vehicle, velocityinformation, inertial information, safety message transmission rate,safety message power level information, and remaining battery power atan MN. Server node 130, which has an overall view of system 100, decideson: (i) whether or not a particular MN should be transmitting and/ormonitoring for safety messages, (ii) safety message monitoringinformation for a particular MN, e.g., a monitoring rate and/or amonitoring duty cycle, when it is decided that the particular MN is tobe monitoring for safety messages, (iii) a rate of transmission ofsafety messages for a particular MN when it is decided that safetymessages should be transmitted by the MN, and (iv) a power level oftransmission of safety messages when it decides that safety messagesshould be transmitted by the MN. The server node 130 generates andtransmits a control message to each of the MNs to control safety messagemonitoring and transmission operations. The control message iscommunicated to the MN via one of the base stations (104, . . . , 106,126, . . . , 128). The MN to which the control message is directedreceives the control message and implements the control operations withregard to safety messages. In this example, MN 1 136 is controlled tomonitor for safety messages at a relatively low rate and to transmitsafety messages at a relatively low rate and relatively low power level.In this example, MN 2 112 is controlled to refrain from monitoring forand transmitting safety messages. In this example, MN 3 193 iscontrolled to monitor for safety messages at a relatively high rate andto transmit safety messages at a relatively high rate and relativelyhigh power level. In this example, MN 4 180 is controlled to monitor forsafety messages at a relatively low rate and to refrain fromtransmitting safety messages. In this example, MN N 183 is controlled tomonitor for safety messages at a relatively high rate and to transmitsafety messages at a relatively high rate and relatively high powerlevel.

In some embodiments, the relatively high monitoring rate is a fixedpredetermined rate HM and the relatively low monitoring rate is a fixedpredetermined rate LM, where rate HM>rate LM. In some embodiments, therelatively high transmission rate is a fixed predetermined rate HT andthe relatively low transmission rate is a fixed predetermined rate LT,where rate HT>rate LT. In some embodiments, the relatively hightransmission power level is a fixed predetermined transmission powerlevel HP and the relatively low transmission power level is a fixedpredetermined transmission power level LP, where HP>LP. In variousembodiments, HT is less than the safety message transmission rate usedby vehicles to transmit basic safety messages.

FIG. 2 is a flowchart 200 of an exemplary method of operating acommunications device in accordance with various embodiments. In someembodiments, the communications device performing the method offlowchart 200 is a mobile communications device, e.g., a portable mobilewireless communications device supporting safety message signaling whichmay be carried by an individual. For example, the communications deviceimplementing the method of flowchart 200 is one of the mobile wirelesscommunications devices (MN 1 136, MN 2 112, MN 3 193, MN 4 180, . . . ,MN N 183) of system 100 of FIG. 1. Operation of the exemplary methodstarts in step 202 where the communications device is powered on andinitialized. Operation proceeds from start step 202 to step 204.

In step 204 the communications device generates location informationbased on at least one of a received signal or inertial guidanceinformation. In some embodiments, the received signal is a GPS signal ora signal received from a cellular network. In some embodiments thereceived signal is from a non-cellular base station. In some embodimentsthe received signal is reference signal from a base station. In someembodiments, the received signal communicates the position of thecommunications device, e.g., a position fix of the communications devicedetermined by a base station or a location determination server, orinformation that can be used to derive the position of thecommunications device. In some embodiments, the received signal is anacoustic signal. In some embodiments, the received signal communicates asafety message, e.g., a safety message from a vehicle. In someembodiments, the received signal is from a communications device of apedestrian. In some such embodiments, the received signal from thepedestrian communicates a safety message. In some embodiments, thereceived signal is an explicit message from a vehicle requestingpedestrians to send safety messages. In various embodiments, theinertial guidance information is obtained and/or derived from inertialmeasurements devices included in the communications device, e.g.,accelerometers and or gyroscopes. In various embodiments, step 204includes one or more of all of optional steps 206, 208, 210, 212 and207. The various steps 206, 208, 210, 212 and 207 may be performedserially, in parallel or in a combination of serial and parallel.

In step 206 the communications device determines a position of thecommunications device relative to a vehicle or vehicular route. In someembodiments, the generated device location information does notdetermine the precise location of the communications device, e.g., anabsolute location, but determines the location of the communicationsdevice relative to a vehicle or vehicular route, e.g., a road, street,train tracks, subway tracks, etc.

In step 208 the communications device determines if the communicationsdevice is located in a vehicle, and in step 210 the communicationsdevice determines if the communications device is located in a movingvehicle. In some embodiments, determining if the communications deviceis located in a vehicle is based on at least one of: user input,strength and/or rate of safety messages received from vehicles, a signalreceived from a safety message system of a vehicle, e.g., the vehicle inwhich the communications device is located, a determined rate of motionrelative to a rate of motion indicative of vehicular motion, or areceived acoustic signal indicative of said communications device beingwithin a vehicle.

Various approaches are used to determine if the communications device islocated in a vehicle and/or if the vehicle is moving. Several approachesare described below. In some embodiments, the communication devicereceives a signal from an on-board DSRC device on the vehicle throughthe safety channel or an external channel signaling that it will betransmitting the safety messages. The communications device checks itsown position with respect to the DSRC device and determines that it iswithin the vehicle.

In some embodiments, the communications device receives GPS signals andidentifies that it is traveling at a velocity and/or direction that arebeyond pedestrian speeds and/or is experiencing accelerations levelsbeyond typical pedestrian acceleration patterns and identifies that itis within a vehicle, e.g., a car.

In some embodiments, the communications device receives safety messagesfrom a plurality of vehicles including nearby vehicles and the vehiclein which it is situated. Consider that the communications deviceobserves that one particular vehicle's position and velocity is veryclose to its own self-determined position and velocity. Thecommunications identifies that it is likely to be within the matchingvehicles' confines.

In some embodiments, the communications device broadcasts a requestsignal which is responded to by the vehicle through 802.11 or Bluetoothor a common communication system. The communications device performs aranging operation by requesting the vehicle to send out audio signalsfrom the vehicle's speakers helping the communications device identifyits position with respect to that vehicle, e.g., determines with anacceptable degree of certainty that the communications device is withinthe vehicle which is transmitting the audio signals.

In some embodiments, a vehicle transmits a particular audio signalwhich, when detected, can be used to identify that the communicationsdevice is located inside the vehicle.

In some embodiments, the communication device receives a signal from anon-board DSRC device on the vehicle through the safety channel or anexternal channel signaling that it will be transmitting the safetymessages. The communications device checks its own position with respectto the DSRC device and determines that it is within the vehicle.

In step 212 the communications device determines if the communicationsdevice is in a building. In various embodiments, the communicationsdevice determines if said communications device is located in a buildingbased on at least one of: user input; a received GPS signal and mapinformation identifying the building location, a communications deviceposition fix based on an RF fingerprint map of the building; a receivedsignal from a mobile device known to be within the building; a signalreceived from a fixed location transmitter within the building; and areceived acoustic signal indicative of said communications device beingwithin the building.

In step 207 the communications device determines a position of thecommunications device relative to other pedestrian users of the DSRCspectrum.

Operation proceeds from step 204 to step 214. In step 214 thecommunications device controls at least one of a safety messagemonitoring operation or safety message transmission operation based onthe generated device location information. In some embodiments, thesafety message is a message including current time, latitude, longitude,speed, heading, vehicle braking information, vehicle throttleinformation, vehicle steering information, vehicle size information,and/or airbag status information. In some embodiments, a safety messageincludes acceleration and/or elevation. In some embodiments, the safetymessage indicates whether the sender is a vehicle or a pedestrian. Insome embodiments, the safety message indicates the type of vehicle. Insome embodiments, the safety message includes at least some user profileinformation obtained from a file stored on the communications device.For example, the user profile information may indicate that the user isblind or that the user is handicapped. In some embodiments, a safetymessage includes some profile information, e.g., information identifyingthat the person carrying the device which transmits the safety messageis walking, information indicating that the person carrying the devicewhich transmits the safety message is cycling, information indicatingthat the person carrying the device which transmits the safety messageis on a particular side of a street, etc. In some embodiments, a safetymessage indicates an intent, e.g., an intent by a vehicle to change alane, an intent by a pedestrian to cross a road, etc. In variousembodiments, the safety message includes information indicating anintent to cross a road. For example, pushing a button on a cell phone isused to generate a safety message to notify a traffic light and othersin an area of an intent to cross a road. In some embodiments, such asafety message may be, and sometimes is, used to control a trafficlight, e.g., change a time at which the traffic light changes to allowthe pedestrian which initialed the safety message to safety cross theroad earlier than would otherwise be the case if the safety message wasnot sent.

In some embodiments, safety messages transmitted by devicescorresponding to pedestrian users include different sets of informationthan safety messages transmitted by devices corresponding to vehicles.For example, a safety message transmitted by a device corresponding to apedestrian may include user profile information, e.g., user ageinformation and user disability information, current time, latitude,longitude, heading, while omitting vehicle specific information such as,e.g., vehicle braking information, vehicle throttle information, vehiclesteering information, vehicle size information, and/or airbag statusinformation which is normally included in a safety message from a motorvehicle mounted device. Examples of user disability information whichmay be included in a pedestrian safety message include, e.g.,information indicating that the user is blind, information indicatingthat the user has limited vision, information indicating that the useris wheelchair restricted, information indicating that the user uses acane, information indicating that the user is deaf, or informationindicating that the user is hearing impaired.

Step 214 includes one or more or all of optional steps 216, 218, 220,222, 224, 226, and 227. In step 216 the communications device enables atleast one of safety message transmission or safety message monitoringoperations when said generated device location information indicatesthat the communications device is outside a vehicle. In step 218 thecommunications device disables at least one of safety messagetransmission or safety message monitoring operations when said generateddevice location information indicates that the communications device isinside a moving vehicle. In step 220 the communications device reducesor disables safety message signaling while the communications device isin a building.

In step 222 the communications device controls a safety messagemonitoring periodicity that determines the time between intervals duringwhich monitoring for safety messages is performed or a safety messagetransmission periodicity that determines the time between safety messagetransmission made by the communications device. In some embodiments, thesafety message monitoring periodicity or the safety message transmissionperiodicity is increased when it is determined that the communicationsdevice is at a location with higher vehicular traffic than at anotherlocation with lower vehicular traffic. In various embodiments, thesafety message monitoring periodicity or the safety message transmissionperiodicity is controlled as a function of proximity to vehiculartraffic. In some embodiments, the safety message transmissionperiodicity is reduced when it is determined that high pedestriantraffic, e.g., above a predetermined threshold, is observed to be usingthe DSRC band. In some such embodiments, the predetermined threshold isa congestion threshold for pedestrian traffic on the DSRC band.

In step 224 the communications device controls the transmission powerlevel of safety messages transmitted by the communications device. Insome embodiments, when the communications device is close to traffic thecommunications device wants its safety messages to be heard by moredevices so it transmits at a higher power level than when it is awayfrom traffic. In some embodiments, if the communications device is faraway from vehicle traffic, the communications device decreases itstransmit power over the transmit power it would use if it was close tovehicle traffic with regard to safety message transmissions to conservepower and to reduce interference for devices which are more likely to bein traffic.

In step 226 the communications device controls the safety messagemonitoring duty cycle. In various embodiments, the safety messagemonitoring duty cycle is controlled as a function of proximity tovehicular traffic, e.g., more safety message monitoring as thecommunications device approach traffic. In various embodiments, thesafety message monitoring duty cycle is controlled as a function of anestimated level of vehicular traffic, e.g., more monitoring for higherlevels of detected vehicular traffic. In various embodiments, the safetymessage monitoring duty cycle is controlled as a function of thepercentage of detected utilized monitored safety message channel, e.g.,more monitoring for higher detected levels of safety message channelutilization.

In step 226 the communications device transmits a safety message signalor adjusts the periodicity of safety message signal transmissions basedon the proximity of the communications device to at least one of theother pedestrian users of the DSRC spectrum.

Operation proceeds from step 214 to step 204 to generate device locationinformation at a later point in time.

In some embodiments, the method of flowchart 200 includes steps 250 and252. In step 250 the communications device receives a message from avehicle requesting pedestrians to send safety messages. Operationproceeds from step 250 to step 252. In step 252 the communicationsdevice transmits at least one safety message in response to saidreceived message from a vehicle requesting pedestrians to send safetymessages. In some embodiments, the received message from the vehiclerequesting pedestrians to send safety messages includes informationcommunicating safety message periodicity information and/or safetymessage transmission power information. In some embodiments, at leastsome safety message transmission operations are controlled in accordancewith step 214.

FIG. 3 is a drawing of an exemplary communications device 300, e.g., amobile wireless device, in accordance with an exemplary embodiment.Exemplary communications device 300 is, e.g., one of the portable mobilewireless devices (136, 112, 193, 180, . . . , 183) of system 100 ofFIG. 1. Communications device 300 may, and sometimes does, implement amethod in accordance with flowchart 200 of FIG. 2.

Communications device 300 includes a processor 302 and memory 304coupled together via a bus 309 over which the various elements (302,304) may interchange data and information. Communications device 300further includes an input module 306 and an output module 308 which maybe coupled to processor 302 as shown. However, in some embodiments, theinput module 306 and output module 308 are located internal to theprocessor 302. Input module 306 can receive input signals. Input module306 includes a wireless receiver 307 for receiving input includingsafety messages. In some embodiments, input module 306 also includes awired or optical input interface for receiving input. Output module 308includes a wireless transmitter 305 for transmitting output includingsafety messages. In some embodiments, output module 308 also includes awired or optical output interface for transmitting output. In variousembodiments, wireless receiver module 307 and wireless transmittermodule 305 form a wireless communications module which supports DSRCsignaling, e.g., 802.11p signaling. In some embodiments, memory 304includes routines 311 and data/information 313.

Communications device 300 further includes wireless communicationsreceive antenna 324 coupled to wireless receiver module 307 and wirelesscommunications transmit antenna 326 coupled to wireless transmittermodule 305. In some embodiments, the same antenna is used for both inputand output wireless communications signaling. Communications device 300further includes a GPS module 316 coupled to GPS antenna 328 via whichthe communications device 300 may receive GPS signals. GPS module 316,e.g., an embedded GPS receiver, processes received GPS signals andoutputs GPS information, e.g., GPS time information, GPS determinedposition fix information, GPS determined velocity information, GPSdetermined altitude information, GPS determined heading information, andGPS accuracy information. Output GPS information is used in determiningdevice location information.

Inertial guidance module 318, e.g., a module including multiplegyroscopes and multiple accelerometers, provides inertial guidanceinformation used in generating device location information. In someembodiments, the inertial guidance module 318 is included as part of anavigation unit included in communications device 300. In someembodiments, the inertial guidance module 318 includes a plurality ofdiscrete inertial measurement components, e.g., discrete accelerometersand/or gyroscopes. In some embodiments, the inertial guidance module 318includes a gyroscope on a chip. In some embodiments, the inertialguidance module 318 includes an accelerometer on a chip. In someembodiments, the inertial guidance module 318 is an inertial measurementunit (IMU) on a chip. In some embodiments, the inertial guidance module318 is included in a chip including processor 302. In variousembodiments, the GPS module 316 is coupled to the inertial guidancemodule 318. In some embodiments, the inertial guidance module 318 aidsthe GPS module 316, e.g., during intervals of poor GPS reception. GPSmodule 316 and inertial guidance module 318 are coupled to bus 309.

Communications device 300 further includes a microphone 330 coupled toan acoustic interface module 332, which is coupled to bus 309. Acousticsignals are detected by microphone 330 and processed by acousticinterface module 332. Exemplary detected acoustic signals include, e.g.,an acoustic signal corresponding to a transmitter located in a building,an acoustic signal corresponding to a transmitter located in a vehicle,an acoustic signal corresponding to a noise profile indicative of beinginside a building, and an acoustic signal corresponding to a noiseprofile indicative of being inside a vehicle. In some embodiments,received acoustic signals are used to identify that the communicationsdevice 300 is located in a building or vehicle. In some embodiments,received acoustic signals are used to perform ranging, e.g., locatingthe communications device 300 within a vehicle with an acceptableprobability.

Communications device 300 further includes a user input module 320 and auser output module 322 coupled to bus 309. User input module 320, e.g.,a keypad and/or touch-screen, receives user input, e.g., user inputidentifying a location, user input identifying that the user is in abuilding, user input indicating that the user is inside a vehicle, userinput indicating that the user intends to cross the street. User outputmodule 322, e.g., a display, presents options to the user in regard tosafety message communications, displays safety message information anddisplays aggregate safety message information.

Communications device 300 further includes a battery power monitoringmodule 334 configured to determine an amount of remaining battery powerfor communications device 300. In some embodiments the determined amountof remaining battery power is used by the communications device 300 incontrolling at least one of a safety message operation and a safetymessage transmission operation. For example, in some embodiments, theamount of time in which the communications device's receiver is poweredon for the purpose of monitoring for safety messages is controlled as afunction of the remaining battery power, e.g., less time for monitoringfor low levels of detected battery power. As another example, the rateof transmission of safety messages and/or the power level oftransmission for safety messages is controlled to be lower when thelevel of remaining battery power is detected to be low.

In various embodiments, processor 302 is configured to: generate devicelocation information based on at least one of a received signal orinertial guidance information; and control at least one of a safetymessage monitoring operation or safety message transmission operationbased on the generated device location information. In some embodiments,said safety message is a message including current time, latitude,longitude, speed, heading, vehicle braking information, vehicle throttleinformation, vehicle steering information, vehicle size information,and/or airbag status information. In some embodiments, said messageindicates whether the sender is in a vehicle or is a pedestrian. Invarious embodiments, said safety message includes at least some userprofile information obtained from a file stored on said communicationsdevice. In some embodiments, safety message includes informationindicating an intent to cross a road.

In various embodiments, processor 302 is configured to determine aposition of the communications device relative to a vehicle or vehicularroute, as part of being configured to generate the device locationinformation. In some embodiments, processor 302 is configured to controla safety message monitoring periodicity that determines the time betweenintervals during which monitoring for safety messages is performed or asafety message transmission periodicity that determines the time betweensafety message transmissions made by said communications device, as partof being configured to control at least one of a safety messagemonitoring operation or transmission operation.

In some embodiments, processor 302 is configured to increase the safetymessage monitoring periodicity or the safety message transmissionperiodicity when it is determined that the communications device is at alocation with higher vehicular traffic than at another location withlower vehicular traffic. In various embodiments, processor 302 isconfigured to control the safety message monitoring periodicity or thesafety message transmission periodicity as a function of proximity tovehicular traffic. In some embodiments, processor 302 is configured toreduce the safety message transmission periodicity when it is determinedthat high pedestrian traffic, e.g., above a predetermined threshold, isobserved to be using the DSRC band.

Processor 302, in some embodiments, is configured to control thetransmission power level of safety messages transmitted by saidcommunications device, as part of being configured to control at leastone of a safety message monitoring operation or safety messagetransmission operation based on the generated device locationinformation.

In various embodiments, processor 302 is configured to disable at leastone of safety message transmission or safety message monitoringoperations when said generated device location information indicatesthat said communications device is inside a moving vehicle, as part ofbeing configured to control at least one of a safety message monitoringoperation or safety message transmission operation based on thegenerated device location information.

In some embodiments, processor 302 is configured to determine if saidcommunications device is located in a vehicle, as part of beingconfigured to generate device location information based on at least oneof a received signal or inertial guidance information. In some suchembodiments, processor 302 is configured to determine if saidcommunications device is located in a vehicle based on at least one of:user input; strength and/or rate of safety messages received fromvehicles; a signal received from a safety message system of a vehicle,e.g., the vehicle in which the communications device is located; adetermined rate of motion relative to a rate of motion indicative ofvehicular motion; or a received acoustic signal indicative of saidcommunications device being within a vehicle.

In various embodiments, processor 302 is configured to enable at leastone of safety message transmission or safety message monitoringoperations when said generated device location information indicatesthat said communications device is outside of a vehicle, as part ofbeing configured to control at least one of a safety message monitoringoperation or safety message transmission operation based on thegenerated device location information.

Processor 302, in some embodiments, is configured to determine if thecommunications device is in a building, as part of being configured togenerate device location information based on at least one of a receivedsignal or inertial guidance information. In some such embodiments,processor 302 is further configured to reduce or disable safety messagesignaling while the communications device is in the building, as part ofbeing configured to control at least one of a safety message monitoringoperation or safety message transmission operation based on thegenerated device location information. In some embodiments, processor302 is configured to determine if said communications device is locatedin a building based on at least one of: user input; a communicationsdevice position fix based on an RF fingerprint map of the building; areceived signal from a mobile device known to be within a building; asignal received from a fixed location transmitter within a building; anda received acoustic signal indicative of said communications devicebeing within a building.

In some embodiments, processor 302 is configured to determine a positionof the communications device relative to other pedestrian users of theDSRC spectrum as part of being configured to generate device locationinformation based on at least one of a received signal or inertialguidance information. In some such embodiments processor 302 isconfigured to transmit a safety message signal or adjust the periodicityof safety message signal transmissions based on the proximity of thecommunications device to at least one of the other pedestrian users ofthe DSRC spectrum.

In some embodiments, processor 302 is configured to receive a messagefrom a vehicle requesting pedestrians to send safety messages. In somesuch embodiments, processor 302 is further configured to transmit atleast one safety message in response to said received message from avehicle requesting pedestrians to send safety messages.

FIG. 4 is an assembly of modules 400 which can, and in some embodimentsis, used in the exemplary communications device 300 illustrated in FIG.3. The modules in the assembly 400 can be implemented in hardware withinthe processor 302 of FIG. 3, e.g., as individual circuits.Alternatively, the modules may be implemented in software and stored inthe memory 304 of communications device 300 shown in FIG. 3. In somesuch embodiments, the assembly of modules 400 is included in routines311 of memory 304 of device 300 of FIG. 3. While shown in the FIG. 3embodiment as a single processor, e.g., computer, it should beappreciated that the processor 302 may be implemented as one or moreprocessors, e.g., computers. When implemented in software the modulesinclude code, which when executed by the processor, configure theprocessor, e.g., computer, 302 to implement the function correspondingto the module. In some embodiments, processor 302 is configured toimplement each of the modules of the assembly of modules 400. Inembodiments where the assembly of modules 400 is stored in the memory304, the memory 304 is a computer program product comprising a computerreadable medium, e.g., a non-transitory computer readable medium,comprising code, e.g., individual code for each module, for causing atleast one computer, e.g., processor 302, to implement the functions towhich the modules correspond.

Completely hardware based or completely software based modules may beused. However, it should be appreciated that any combination of softwareand hardware (e.g., circuit implemented) modules may be used toimplement the functions. As should be appreciated, the modulesillustrated in FIG. 4 control and/or configure the communications device300 or elements therein such as the processor 302, to perform thefunctions of the corresponding steps illustrated and/or described in themethod of flowchart 200 of FIG. 2.

FIG. 4 is an assembly of modules 400 in accordance with variousembodiments. Assembly of modules 400 includes a module 404 configured togenerate device location information based on at least one of a receivedsignal or inertial guidance information and a module 414 configured tocontrol at least one of a safety message monitoring operation or safetymessage transmission operation based on the generated device locationinformation. Module 404 includes a module 406 configured to determine aposition of the communications device relative to a vehicle or vehicularroute, a module 408 configured to determine if the communications deviceis located in a vehicle, a module 410 configured to determine if thecommunications device is located in a moving vehicle, a module 412configured to determine if the communications device is in a building,and a module 407 configured to determine a position of thecommunications device relative to other pedestrian users of the DSRCspectrum. In some embodiments, one or more of all of modules 406, 408,410, 412 and 407 are located outside module 404.

Module 404 further includes a position comparison module 411, apedestrian dynamic profile comparison module 413, a vehicle dynamicprofile comparison module 415, a position/velocity matching module 417,an audio signal request module 419 an audio signal module 421. Outputsfrom one or more of modules 411, 413, 415, 417, 419 and 421 are used bymodule 406, 408 and/or module 410 to make a determination. Positioncomparison module 411 is configured to compare the position of thecommunications device including assembly of modules 400 to a positionreceived from a safety message from a vehicle and determined whether thecommunications device including assembly of modules 400 is within thevehicle. Pedestrian dynamic profile comparison module 413 is configuredto determine the traveling velocity, acceleration, and heading of thecommunications device in which assembly of modules 400 is located, e.g.,based on received GPS signals and/or internal inertial sensors, e.g.,gyroscopes and accelerometers, and determine whether or not the velocityexceeds pedestrian speeds, whether or not the determined accelerationprofile is outside an expected pedestrian profile, and whether or notthe heading is outside a typical pedestrian route, e.g., the route beingtravelled is along a sidewalk or hiking path. Vehicle dynamic profilecomparison module 415 is configured to determine the traveling velocity,acceleration, and heading of the communications device in which assemblyof modules 400 is located, e.g., based on received GPS signals and/orinternal inertial sensors, e.g., gyroscopes and accelerometers, anddetermine whether or not the velocity is within the envelope forexpected vehicle speeds and whether or not the acceleration profilematches an expected vehicle profile, and whether or not the heading isfollowing a typical vehicle route, e.g., the route being travelled isalong a lane of a highway, along a railroad track or along a subwaytrack. In some embodiments, different profiles corresponding todifferent types of vehicles are stored in memory and the vehicle dynamicprofile module 415 identifies which type of vehicle the communicationsdevice including assembly of modules 400 is located in, e.g., a car or atrain. Position/velocity matching module 417 compares the position andvelocity of the communications device including assembly of modules 400to a plurality of sets of received position/velocity information fromreceived safety messages from a plurality of vehicles in the vicinityand determines which one vehicle has position and velocity which is thebest match to the position and velocity information for thecommunications device including assembly of modules 400, e.g.,identifying which vehicle the communications device is located in. Audiosignal request module 419 requests, e.g., requests a vehicle, to sendaudio signals from its speakers to help identify the position of thecommunications device including assembly of modules 400, e.g., todetermine if the communications device including assembly of modules 400is within the vehicle within an acceptable degree of certainty. Audiosignal module 421 performs a ranging operation by processing receivedaudio signals, e.g., received audio signals which were transmitted overa plurality of the vehicle's speakers, e.g., in response to a request,and determines whether or not the communications device includingassembly of modules 400 is within the vehicle. In some embodiments, thetransmitted audio signals used for ranging are intentionally chosen touse frequencies in a range which are not audibly detectable by themajority of humans but which are detectable by the communications deviceincluding assembly of modules 400.

Module 414 includes: a module 416 configured to enable at least one ofsafety message transmission or safety message monitoring operations whensaid generated device location information indicates that thecommunications device is outside a vehicle, a module 418 configured todisable at least one of safety message transmission or safety messagemonitoring operations when said generated device location informationindicates that the communications device is inside a moving vehicle, anda module 420 configured to reduce or disable safety message signalingwhile the communications device is in a building. Module 414 furtherincludes a module 422 configured to control safety message monitoringperiodicity that determines the times between intervals during whichmonitoring for safety messages is performed or a safety messagetransmission periodicity that determines the time between safety messagetransmissions made by the communications device, and a module 424configured to control the transmission power level of safety messagestransmitted by the communications device. Module 414 further includes amodule 426 configured to control a safety message monitoring duty cycle.Module 414 further includes a module 427 configured to transmit a safetymessage signal or adjust the periodicity of safety message signaltransmissions based on the proximity of the communications device to atleast one of the other pedestrian users of the DSRC spectrum. In someembodiments, one or more of all of modules 416, 418, 420, 422, 424, 426,and 427 are located outside module 414.

In some embodiments said safety message is a message including currenttime, latitude, longitude, speed, heading, vehicle braking information,vehicle throttle information, vehicle steering information, vehicle sizeinformation, and/or airbag status information. In various embodiments,said safety message indicates whether the sender is in a vehicle or is apedestrian. In some embodiments, said safety message includes at leastsome user profile information obtained from a file stored on saidcommunications device. In some embodiments, said safety message includesinformation indicating an intent to cross a road.

In various embodiments, the module 422, configured to control a safetymessage monitoring periodicity or a safety message transmissionperiodicity, controls the safety message monitoring periodicity or thesafety message transmission periodicity to increase when it isdetermined that the communications device has moved to a location withhigher vehicular traffic from another location with lower vehiculartraffic.

In various embodiments, module 422, configured to control a safetymessage monitoring periodicity or safety message transmissionperiodicity, controls the safety message monitoring periodicity or thesafety message transmission periodicity as a function of proximity tovehicular traffic. In some such embodiments, the control is such thatthe safety message monitoring or safety message transmission occurs morefrequently when the communications device is close to vehicular trafficthan when the communications device is far away from vehicle traffic.

In various embodiments, module 422, configured to control a safetymessage monitoring periodicity or safety message transmissionperiodicity, controls the safety message monitoring periodicity or thesafety message transmission periodicity as a function of vehicular speedin the vicinity. In some such embodiments, the control is such that thesafety message monitoring or safety message transmission occurs morefrequently when the communications device is in a region with highvehicular speeds than when the communications device is in a region withlow vehicular speeds. In some embodiments, the control is such that thesafety message monitoring or safety message transmission occurs morefrequently when the communications device is in a region with a highposted speed limit than when the communications device is in a regionwith low posted speed limit.

In various embodiments module 422, configured to control safety messagemonitoring periodicity or safety message transmission periodicity,controls the safety message monitoring periodicity or safety messagetransmission periodicity as a function of the type of vehicle or type ofvehicles allowed in the vicinity, e.g., bicycle, motorcycle, car, truck,bus, train, tram, and/or subway vehicle. In various embodiments module422, configured to control safety message monitoring periodicity orsafety message transmission periodicity, controls the safety messagemonitoring periodicity or safety message transmission periodicity as afunction of the type of vehicle or type of vehicles detected to be inthe vicinity, e.g., bicycle, motorcycle, car, truck, bus, train, tram,and/or subway vehicle.

In some embodiments, module 422 controls the safety message transmissionperiodicity as a function of the amount of pedestrian traffic observedto be using the DSRC band. In some embodiments, module 422 controls thesafety message transmission periodicity to operate at a reduced ratewhen it is determined that high pedestrian traffic, e.g., above apredetermined threshold, is observed to be using the DSRC band.

In some embodiments, module 408, configured to determine if saidcommunications device is located in a vehicle, determines if thecommunications device is located in a vehicle based on at least one of:user input; strength and/or rate of safety messages received fromvehicles; a signal received from a safety message system of a vehicle; adetermined rate of motion relative to a rate of motion indicative ofvehicular motion; or a received acoustic signal indicative of saidcommunications device being within a vehicle.

Assembly of modules 400 further includes a module 450 configured toreceive a message from a vehicle requesting pedestrians to send safetymessages and a module 452 configured to transmit at least one safetymessage in response to said message from a vehicle requestingpedestrians to send safety messages.

FIG. 5 is a flowchart 500 of an exemplary method of operating acommunications device in accordance with various embodiments. In someembodiments, the communications device performing the method offlowchart 500 is a network node, e.g., a server node or a base station.The communications device performing the method of flowchart 500 is,e.g., server node 130 or base station 126 or base station 105 of system100 of FIG. 1. Operation of the exemplary method starts in step 502where the communications device is powered on and initialized. Operationproceeds from start step 502 to step 504. The steps of flowchart 500 maybe performed by the communications device for each of a plurality ofmobile wireless communications devices which are being controlled by thecommunications device with regard to at least one safety messagemonitoring operations or safety message transmission operations. Forexample, in one embodiment server node 130 is controlling mobilewireless communications devices (MN 1 136, MN 2 112, MN 3 193, MN 4 180,. . . , MN N 183) with regard to safety message monitoring and/or safetymessage transmission operations.

In step 504 the communications device generates location informationbased on at least one of a received signal or inertial guidanceinformation. In some embodiments, the received signal is a GPS signal ora signal received from a cellular network. In some embodiments, a mobilewireless communications device determined position fix is communicatedto the communications device implementing the method of flowchart 500,e.g., via the cellular network and/or the backhaul. In some embodiments,information used to derive the position of the mobile wirelesscommunications device, e.g., power strength measurements of receivedreference signals, is communicated from the mobile wirelesscommunications device to the communications device implementing themethod of flowchart 500. In some embodiments, a mobile wirelesscommunications device determines its position, e.g., based on GPS and/orinertial measurements, and communicates its determined position to thecommunications device implementing the method of flowchart 500. Invarious embodiments, step 504 includes one or more of all of optionalsteps 506, 508, 510, 512, and 507. In step 506 the communications devicedetermines a position of the mobile wireless communications devicerelative to a vehicle or vehicular route. In some embodiments, thegenerated device location information does not determine the preciselocation of the communications device, e.g., an absolute location, butdetermines the location of the communications device relative to avehicle or vehicular route, e.g., a road, street, train tracks, subwaytracks, etc. In some embodiments, the communications device implementingthe method of flowchart 500, which has a more accurate overall view ofthe situation in the vicinity of mobile wireless communications devicethan the mobile wireless communications device, includes a map and isable to locate the mobile communications device relative to othervehicles, streets, etc. In step 508 the communications device determinesif the mobile wireless communications device is located in a vehicle,and in step 510 the communications device determines if the mobilewireless communications device is located in a moving vehicle. In someembodiments, determining if the mobile wireless communications device islocated in a vehicle is based on at least one of: user input, strengthand/or rate of safety messages received from vehicles, a signal receivedfrom a safety message system of a vehicle, e.g., the vehicle in whichthe mobile wireless communications device is located, a determined rateof motion of the mobile wireless communications device relative to arate of motion indicative of vehicular motion, or a received acousticsignal by the mobile wireless communications device indicative of saidmobile wireless communications device being within a vehicle. In step512 the communications device determines if the mobile wirelesscommunications device is in a building. In various embodiments, thecommunications device determines if said mobile wireless communicationsdevice is located in a building based on at least one of: user input; acommunications device position fix based on an RF fingerprint map of thebuilding; a received signal from another mobile wireless communicationsdevice known to be within the building; a signal received by the mobilewireless communications device from a fixed location transmitter withinthe building; and a received acoustic signal by the mobile wirelesscommunications device indicative of said mobile wireless communicationsdevice being within the building. In step 507 the communications devicedetermines the position of the mobile wireless communications devicerelative to the position of other pedestrian users of the DSRC spectrum.

Operation proceeds from step 504 to step 514. In step 514 thecommunications device controls at least one of a safety messagemonitoring operation or safety message transmission operation based onthe generated device location information. In some embodiments, thesafety message is a message including current time, latitude, longitude,speed, heading, vehicle braking information, vehicle throttleinformation, vehicle steering information, vehicle size information,and/or airbag status information. In some such embodiments, the safetymessage indicates whether the sender is a vehicle or a pedestrian. Insome embodiments, the safety message includes at least some user profileinformation obtained from a file stored on the communications devicesending the safety message. For example, the user profile informationmay indicate that the user is blind or that the user is handicapped. Invarious embodiments, the safety message includes information indicatingan intent to cross a road. For example, pushing a button on a cell phoneis used to generate a safety message to notify a traffic light andothers in an area of an intent to cross a road.

Step 514 includes one or more or all of optional steps 516, 518, 520,522, and 524. Step 514 also includes steps 526 and 528. In step 516 thecommunications device enables at least one of safety messagetransmission or safety message monitoring operations when said generateddevice location information indicates that the mobile wirelesscommunications device is outside a vehicle. In step 518 thecommunications device disables at least one of safety messagetransmission or safety message monitoring operations when said generateddevice location information indicates that the mobile wirelesscommunications device is inside a moving vehicle. In step 520 thecommunications device reduces or disables safety message signaling whilethe mobile wireless communications device is in a building. In step 522the communications device controls a safety message monitoringperiodicity that determines the time between intervals during whichmonitoring for safety messages is performed or a safety messagetransmission periodicity that determines the time between safety messagetransmission made by the mobile wireless communications device. In someembodiments, the safety message monitoring periodicity or the safetymessage transmission periodicity is increased when it is determined thatthe mobile wireless communications device is at a location with highervehicular traffic than at another location with lower vehicular traffic.In various embodiments, the safety message monitoring periodicity or thesafety message transmission periodicity is controlled as a function ofproximity of the mobile wireless communications device to vehiculartraffic. In various embodiments, the safety message transmissionperiodicity is controlled as a function of the observed level ofpedestrian traffic using the DSRC band. For example, in response to adetected high level of pedestrian traffic using the DSRC band, e.g.,above a predetermined pedestrian traffic threshold level, the number ofsafety messages transmitted from the mobile communications device in agiven time interval is reduced, e.g., to reduce congestion in the DSRCband. In step 524 the communications device controls the transmissionpower level of safety messages transmitted by the mobile wirelesscommunications device. In some embodiments, when the mobile wirelesscommunications device is close to traffic the communications devicewants the mobile wireless communication device's safety messages to beheard by more devices so it is controlled to transmit at a higher powerlevel than when the mobile wireless communications device is away fromtraffic. In some embodiments, if the mobile wireless communicationsdevice is far away from vehicle traffic the communications devicecontrols the mobile wireless communications device to decrease itstransmit power over the transmit power it would use if it was close tovehicle traffic with regard to safety message transmissions to conservepower and to reduce interference for devices which are more likely to bein traffic.

Operation proceeds from one or more of steps 515, 518, 520, 522 and 524to step 526. In step 526 the communications device generates a controlmessage for controlling at least one of a safety message monitoringoperation or safety message transmission operation of the mobilewireless communications device. In step 526 the communications deviceincorporates information in the generated control message to implementthe decisions of one or more of steps 516, 518, 520, 522 and 524.Operation proceeds from step 526 to step 528. In step 528 thecommunications device transmits the generated control message to themobile wireless communications device. In some embodiments, thetransmitted message is communicated from the communications deviceimplementing the method of flowchart 500 to the mobile wirelesscommunications device through a backhaul network and a wirelesscommunications channel, e.g., a cellular communications signal. In someembodiments, the control message from the communications deviceimplementing the method of flowchart 500 to the wireless communicationsdevice communicates a command, e.g., a command to enable or disablesafety message monitoring and/or safety message transmission operations,a command communicating a safety message transmission periodicity, acommand communicating safety message monitoring periodicity information,a command indicating a safety message transmission power level, acommand communicating a maximum allowed safety message transmissionperiodicity, a command indicating a maximum allowed safety messagetransmission power level. Operation proceeds from step 514 to step 504to generate device location information corresponding to the mobilewireless communications device at a later point in time.

In some embodiments, including step 507, the communications devicecontrols the mobile wireless communications device to transmit a safetymessage signal or controls the mobile wireless communications device toadjust the periodicity of safety message signal transmissions based onthe proximity of the mobile wireless communications device to at leastone of the pedestrian uses of the DSRC spectrum. In some suchembodiments, control information to implement the control is included ina generated control message in step 526 and the generated controlmessage is transmitted in step 528.

FIG. 6 is a drawing of an exemplary communications device 600, e.g.,network device such as a server node or base station node, in accordancewith an exemplary embodiment. Exemplary communications device 600 is,e.g., one of server nodes or base station nodes of system 100 of FIG. 1.Communications device 600 may, and sometimes does, implement a method inaccordance with flowchart 500 of FIG. 5. Communications device 600controls at least one of safety message monitoring operations or safetymessage transmission operations for a plurality of mobile wirelesscommunications devices.

Communications device 600 includes a processor 602 and memory 604coupled together via a bus 609 over which the various elements (602,604) may interchange data and information. Communications device 600further includes an input module 606 and an output module 608 which maybe coupled to processor 602 as shown. However, in some embodiments, theinput module 606 and output module 608 are located internal to theprocessor 602. Input module 606 can receive input signals. Input module606 can, and in some embodiments does, include a wireless receiverand/or a wired or optical input interface for receiving input. Outputmodule 608 may include, and in some embodiments does include, a wirelesstransmitter and/or a wired or optical output interface for transmittingoutput. In some embodiments, memory 604 includes routines 611 anddata/information 613.

In various embodiments, processor 602 is configured to: generate devicelocation information based on at least one of a received signal orinertial guidance information; and control at least one of a safetymessage monitoring operation or safety message transmission operationbased on the generated device location information. In some embodiments,said safety message is a message including current time, latitude,longitude, speed, heading, vehicle braking information, vehicle throttleinformation, vehicle steering information, vehicle size information,and/or airbag status information. In some such embodiments, said messageindicates whether the sender is in a vehicle or is a pedestrian. Invarious embodiments, said safety message includes at least some userprofile information obtained from a file stored on said communicationsdevice transmitting the safety message. In some embodiments, safetymessage includes information indicating an intent to cross a road by thedevice transmitting the safety message.

In various embodiments, processor 602 is configured to determine aposition of a mobile wireless communications device relative to avehicle or vehicular route, as part of being configured to generate thedevice location information. In some embodiments, processor 602 isconfigured to control a safety message monitoring periodicity thatdetermines the time between intervals during which monitoring for safetymessages is performed or a safety message transmission periodicity thatdetermines the time between safety message transmissions made by saidmobile wireless communications device, as part of being configured tocontrol at least one of a safety message monitoring operation ortransmission operation.

In some embodiments, processor 602 is configured to increase the safetymessage monitoring periodicity or the safety message transmissionperiodicity when it is determined that the mobile wirelesscommunications device is at a location with higher vehicular trafficthan at another location with lower vehicular traffic. In variousembodiments, processor 602 is configured to control the safety messagemonitoring periodicity or the safety message transmission periodicity ofthe mobile wireless communications device as a function of proximity tovehicular traffic.

Processor 602, in some embodiments, is configured to control thetransmission power level of safety messages transmitted by said mobilewireless communications device, as part of being configured to controlat least one of a safety message monitoring operation or safety messagetransmission operation based on the generated device locationinformation.

In various embodiments, processor 602 is configured to disable at leastone of safety message transmission or safety message monitoringoperations of the mobile wireless communications device when saidgenerated device location information indicates that said mobilewireless communications device is inside a moving vehicle, as part ofbeing configured to control at least one of a safety message monitoringoperation or safety message transmission operation based on thegenerated device location information.

In some embodiments, processor 602 is configured to determine if saidmobile wireless communications device is located in a vehicle, as partof being configured to generate device location information based on atleast one of a received signal or inertial guidance information. In somesuch embodiments, processor 602 is configured to determine if saidmobile wireless communications device is located in a vehicle is basedon at least one of: user input; strength and/or rate of safety messagesreceived from vehicles; a signal received from a safety message systemof a vehicle (e.g., the vehicle in which the communications device islocated); a determined rate of motion of the mobile wirelesscommunications device relative to a rate of motion indicative ofvehicular motion; or a received acoustic signal received by the mobilewireless communications device indicative of said mobile wirelesscommunications device being within a vehicle.

In various embodiments, processor 602 is configured to enable at leastone of safety message transmission or safety message monitoringoperations for the mobile wireless communications device when saidgenerated device location information indicates that said mobilewireless communications device is outside of a vehicle, as part of beingconfigured to control at least one of a safety message monitoringoperation or safety message transmission operation based on thegenerated device location information.

Processor 602, in some embodiments, is configured to determine if themobile wireless communications device is in a building, as part of beingconfigured to generate device location information based on at least oneof a received signal or inertial guidance information. In some suchembodiments, processor 602 is further configured to reduce or disablesafety message signaling while the mobile wireless communications deviceis in the building, as part of being configured to control at least oneof a safety message monitoring operation or safety message transmissionoperation based on the generated device location information. In someembodiments, processor 602 is configured to determine if said mobilewireless communications device is located in a building based on atleast one of: user input; a position fix of the mobile wirelesscommunications device based on an RF fingerprint map of the building; areceived signal from another mobile device known to be within abuilding; a signal received by the mobile wireless communications devicefrom a fixed location transmitter within a building; and a receivedacoustic signal indicative of said mobile wireless communications devicebeing within a building.

In some embodiments, processor 602 is configured to determine thelocation of the mobile wireless communications device relative to theposition of other pedestrian users of the DSRC spectrum. In some suchembodiments, processor 602 is further configured to control the mobilewireless communications device to transmit a safety message signal oradjust the periodicity of safety message signaling based on theproximity of the mobile wireless communications device to at least oneother pedestrian user of the DSRC spectrum.

In various embodiments, processor 602 is configured to generate acontrol message for controlling at least one of a safety messagemonitoring operation or a safety message transmission operation of themobile wireless communications device, e.g., a control messagecommunicating control decisions with regard to safety message monitoringactivation and rates and/or with regard to safety message transmissionactivation, rates, and transmission power levels for the mobile wirelesscommunications device being controlled. Processor 602 is furtherconfigured to transmit, e.g., directly or indirectly, the generatedcontrol message to the mobile wireless communications device beingcontrolled.

FIG. 7 is an assembly of modules 700 which can, and in some embodimentsis, used in the exemplary communications device 600 illustrated in FIG.6. The modules in the assembly 700 can be implemented in hardware withinthe processor 602 of FIG. 6, e.g., as individual circuits.Alternatively, the modules may be implemented in software and stored inthe memory 604 of communications device 600 shown in FIG. 6. In somesuch embodiments, the assembly of modules 700 is included in routines611 of memory 604 of device 600 of FIG. 6. While shown in the FIG. 6embodiment as a single processor, e.g., computer, it should beappreciated that the processor 602 may be implemented as one or moreprocessors, e.g., computers. When implemented in software the modulesinclude code, which when executed by the processor, configure theprocessor, e.g., computer, 602 to implement the function correspondingto the module. In some embodiments, processor 602 is configured toimplement each of the modules of the assembly of modules 700. Inembodiments where the assembly of modules 700 is stored in the memory604, the memory 604 is a computer program product comprising a computerreadable medium, e.g., a non-transitory computer readable medium,comprising code, e.g., individual code for each module, for causing atleast one computer, e.g., processor 602, to implement the functions towhich the modules correspond.

Completely hardware based or completely software based modules may beused. However, it should be appreciated that any combination of softwareand hardware (e.g., circuit implemented) modules may be used toimplement the functions. As should be appreciated, the modulesillustrated in FIG. 7 control and/or configure the communications device600 or elements therein such as the processor 602, to perform thefunctions of the corresponding steps illustrated and/or described in themethod of flowchart 500 of FIG. 5.

FIG. 7 is an assembly of modules 700 in accordance with variousembodiments. Assembly of modules 700 includes a module 704 configured togenerate device location information based on at least one of a receivedsignal or inertial guidance information and a module 714 configured tocontrol at least one of a safety message monitoring operation or safetymessage transmission operation based on the generated device locationinformation. Module 704 includes a module 706 configured to determine aposition of a mobile wireless communications device relative to avehicle or vehicular route, a module 708 configured to determine if themobile wireless communications device is located in a vehicle, a module710 configured to determine if the mobile wireless communications deviceis located in a moving vehicle, and a module 712 configured to determineif the mobile wireless communications device is in a building. Module704 includes a module 707 configured to determine the position of themobile wireless communications device relative to the position of otherpedestrian users of the DSRC spectrum. In some embodiments, one or moreof all of modules 706, 708, 710, 712, and 707 are located outside module704.

Module 714 includes a module 716 configured to enable at least one ofsafety message transmission or safety message monitoring operations whensaid generated device location information indicates that the mobilewireless communications device is outside a vehicle, a module 718configured to disable at least one of safety message transmission orsafety message monitoring operations when said generated device locationinformation indicates that the mobile wireless communications device isinside a moving vehicle, and a module 720 configured to reduce ordisable safety message signaling while the mobile wirelesscommunications device is in a building. Module 714 further includes amodule 722 configured to control safety message monitoring periodicitythat determines the times between intervals during which monitoring forsafety messages is performed or a safety message transmissionperiodicity that determines the time between safety messagetransmissions made by the mobile wireless communications device and amodule 724 configured to control the transmission power level of safetymessages transmitted by the mobile wireless communications device.Module 714 further includes a module 725 configured to control themobile wireless communications device to transmit a safety messagesignal or adjust the periodicity of safety message signal transmissionsbased on the proximity of the mobile wireless communications device toat least one of the other pedestrian users of the DSRC spectrum.

Module 714 further includes a module 726 configured to generate acontrol message for controlling at least one of a safety messagemonitoring operation or a safety message transmission operation of amobile wireless communications device and a module 728 configured totransmit the generated control message to a mobile wirelesscommunications device. In some embodiments, one or more of all ofmodules 716, 718, 720, 722, 724, 725, 726 and 728 are located outsidemodule 714.

In some embodiments a safety message is a message including currenttime, latitude, longitude, speed, heading, vehicle braking information,vehicle throttle information, vehicle steering information, vehicle sizeinformation, and/or airbag status information. In various embodiments, asafety message indicates whether the sender is in a vehicle or is apedestrian. In some embodiments, said safety message includes at leastsome user profile information obtained from a file stored on the devicewhich transmitted the message. In some embodiments, said safety messageincludes information indicating an intent to cross a road.

In various embodiments, the module 722, configured to control a safetymessage monitoring periodicity or a safety message transmissionperiodicity, controls the safety message monitoring periodicity or thesafety message transmission periodicity to increase when it isdetermined that the mobile wireless communications device has moved to alocation with higher vehicular traffic from another location with lowervehicular traffic.

In various embodiments, module 722, configured to control a safetymessage monitoring periodicity or safety message transmissionperiodicity, controls the safety message monitoring periodicity or thesafety message transmission periodicity as a function of proximity ofthe mobile wireless communications device to vehicular traffic. In somesuch embodiments, the control is such that the safety message monitoringor safety message transmission is controlled to occur more frequentlywhen the mobile wireless communications device is close to vehiculartraffic than when the mobile wireless communications device is far awayfrom vehicle traffic.

In various embodiments, module 722, configured to control a safetymessage monitoring periodicity or safety message transmissionperiodicity, controls the safety message monitoring periodicity or thesafety message transmission periodicity as a function of vehicular speedin the vicinity of the mobile wireless communications device that isbeing controlled. In some such embodiments, the control is such that thesafety message monitoring or safety message transmission occurs morefrequently when the mobile wireless communications device is in a regionwith high vehicular speeds than when the mobile wireless communicationsdevice is in a region with low vehicular speeds. In some embodiments,the control is such that the safety message monitoring or safety messagetransmission occurs more frequently when the mobile wirelesscommunications device is in a region with a high posted speed limit thanwhen the mobile wireless communications device is in a region with lowposted speed limit.

In various embodiments module 722, configured to control safety messagemonitoring periodicity or safety message transmission periodicity,controls the safety message monitoring periodicity or safety messagetransmission periodicity as a function of the type of vehicle or type ofvehicles allowed in the vicinity of the mobile wireless communicationsdevice being controlled, e.g., bicycle, motorcycle, car, truck, bus,train, tram, subway vehicle, etc. In various embodiments module 722,configured to control safety message monitoring periodicity or safetymessage transmission periodicity, controls the safety message monitoringperiodicity or safety message transmission periodicity as a function ofthe type of vehicle or type of vehicles detected to be in the vicinityof the mobile wireless communications device being controlled, e.g.,bicycle, motorcycle, car, truck, bus, train, tram, subway train, etc.

In some embodiments, module 722 is configured to control the safetymessage transmission periodicity as a function of the amount of observedpedestrian traffic using the DSRC band in the vicinity of the mobilewireless communications device being controlled. For example, forobserved high levels of pedestrian traffic using the DSRC band in thevicinity of the mobile wireless communications device being controlledthe mobile wireless communications device being controlled is controlledto transmit safety messages less frequently, e.g., to reduce congestion.

In some embodiments, module 708, configured to determine if a mobilecommunications device is located in a vehicle, determines if a mobilewireless communications device is located in a vehicle based on at leastone of: user input to the mobile wireless communications device;strength and/or rate of safety messages received from vehicles by themobile wireless communications device; a signal received from a safetymessage system of a vehicle by the mobile wireless communicationsdevice; a determined rate of motion of the mobile wirelesscommunications device relative to a rate of motion indicative ofvehicular motion; or a received acoustic signal received by said mobilewireless communications device indicative of said mobile wirelesscommunications device being within a vehicle.

Various aspects and/or features of some, but not necessarily allembodiments, are further described below. In some embodiments, the powerand/or periodicity of a safety message sent by a wireless device isadjusted according to the environment. The environmental inputs whichmay be, and sometimes are, used include, e.g., GPS signals received bythe wireless device, wireless device inertial system measurements madeby instruments such as gyroscopes and accelerometers which can be usedto predict the position of a pedestrian with the wireless device, andbasic safety messages from other vehicles, e.g., 802.11p transmissionsfrom vehicles.

For example, if GPS signals used in conjunction with maps indicate thatthe user is within a building or in an indoor setting the transmissionsof safety messages, in some embodiments, is completely switched off orreduced, e.g., reduced to less than one transmission a second. Inaddition to GPS signals, the phone's inertial systems such as gyroscopesmay be used to predict the position/direction of travel of a pedestrian.If the pedestrian is not close to the road traffic, the periodicity maybe reduced and increased at a later point in time when the pedestriangets close to road traffic again. The detection of road traffic basicsafety messages from other vehicles, e.g., 802.11p transmissions fromthe other vehicles, and their received power may, and sometimes is, alsoused, to indicate how close to the road/traffic the users are.

Various exemplary embodiments, may, and sometimes do, use one or more orall of the above inputs to identify when a pedestrian's mobile wirelessdevice is to be controlled to transmit safety messages, e.g., when thepedestrian attempts to cross the road, and to reduce the periodicity toa low value, e.g., 1 transmission per second or lower, if identified notto be in a traffic related scenario.

Since a significant amount of energy is also spent in keeping thereceiver for the 802.11p signal on, it can be useful to regulate thereceiver duty cycle in the wireless device based on its environment,particularly when battery drain is an important consideration.Controlling the reception duty cycles can also utilize the inputs fromthe above inputs, e.g., GPS, gyroscope/accelerometer, and detected802.11p transmissions. The duty cycle of observing the safetytransmissions may be, and in some embodiments, is reduced based on theestimated position/activity of the pedestrian, and if he/she is inproximity to roads and traffic.

Further, the duty-cycle of observing the 802.11p transmissions may bebased on the density of the channel occupancy within the observedduration and also the received power. For example, if a phone receiveris in a current state of observing the channel for 100 ms duration every1 second and within this 100 ms duration it observes a channel occupancygreater than 50%, it implies that the receiver is close to vehiculartransmissions. Channel occupancy can be measured from vehicles (themeasurement is more reliable) or from other pedestrians (this is lessreliable).

Similarly, if basic safety message (BSM) packets from a few vehicles arereceived at very high power, it again implies that the pedestrian isvery close to vehicular traffic, and as a response, the duty cycle, insome embodiments, is increased and the receiver is kept in an ON statefor a longer fraction of the time.

Similarly, if the 802.11p basic safety messages become extremely weak orthe channel occupancy is really low, the pedestrian device switches to alower periodicity of hearing the channel.

Various aspects and/or features of controlling transmission of safetymessages will be further discussed below. In some embodiments, the powerand periodicity of a pedestrian transmitter is controlled based on theidentified environment and situation the pedestrian is in. Exemplaryinputs used to identify the environment include: GPS signals received bythe phone/device, measurement by the phone/device's inertial systemcomponents such as measurements by gyroscopes and accelerometers whichare used to predict the position of a pedestrian, and the detection ofroad traffic basic safety messages from other vehicles, e.g., 802.11ptransmissions from other vehicles.

If the GPS signals used in conjunction with maps indicate that the useris within a building or in an indoor setting, in some embodiments, thetransmissions of safety messages are either completely switched off orreduced, e.g., reduced to less than one transmission a second. Inaddition to GPS signals, the phone's inertial systems such as gyroscopesare used to predict the position/direction of travel of a pedestrian. Ifthe pedestrian is not very close to the road traffic, the periodicity isreduced and may be increased at a later point in time when the user getscloser to the road traffic. The detection of road traffic basic safetymessages from other vehicles, e.g., 802.11p transmissions, and theirreceived power also indicate how close to the road/traffic the usersare.

Various embodiments, use one or more or all the above inputs to identifywhen a pedestrian's mobile wireless communications device is controlledto transmit safety messages, e.g., when the pedestrian attempts to crossthe road, and to reduce the periodicity to a low value, e.g., 1transmission per second or lower, if identified to be not in a trafficrelated scenario.

Various aspects and/or features of some embodiments of controllingreception of safety messages, e.g., switching the receiver on to receivesafety messages, is further discussed below. Since a significant amountof energy is also spent in keeping the receiver for the 802.11p signalon, it is useful to regulate the receiver duty cycle in the mobilewireless communications device based on its environment.

Controlling the reception duty cycles, in some embodiments, utilizes theinputs from the above inputs, e.g., GPS inputs, gyroscope/accelerometerinputs, 802.11p transmission detection information. The duty cycle ofobserving the safety message transmissions can be, and in someembodiments, is reduced based on the estimated position and/or estimatedactivity of the pedestrian and if he/she is in proximity to roads andtraffic.

Further, the duty-cycle of observing the 802.11p transmissions, e.g.,monitoring 802.11p transmission, in some embodiments, is based on thedensity of the channel occupancy within the observed duration and alsothe received power. For example, in some embodiments, if a mobile phonereceiver is in a current state of observing the channel for a 100 msduration every 1 second and within this 100 ms duration it observes achannel occupancy greater than 50%, it implies that the receiver isclose to vehicular transmissions. Similarly, if BSM packets from a fewvehicles are received at very high power, it again implies that thepedestrian is very close to vehicular traffic, and, in some embodiments,as a response, the duty cycle is increased and the receiver is kept inan ON state for a longer fraction of the time.

Similarly, if the detected 802.11p basic safety messages observed by themonitoring become extremely weak or the channel occupancy is observed tobe really low, in some embodiments, the pedestrian device switches to alower periodicity of hearing, e.g., monitoring, the channel.

The issues of controlling transmission of a portable wirelesscommunications device vary depending on whether the device is locatedinside a vehicle, e.g., inside a car with DSRC communicationscapability. Various features are directed to determining if a portabledevice, e.g., cellphone, is within a vehicle, e.g., a car in which caseit may disable its DSRC safety messaging capability for the period oftime it is within the car.

In some embodiments, a cellphone device can identify that it is within amoving vehicle, e.g., a moving car. In some such embodiments, thecellphone shuts off its DSRC safety messages in response to determiningthat it is within a moving vehicle which is transmitting and monitoringfor DSRC messages.

In one embodiment, the cellphone device receives a signal from theon-board DSRC device on the vehicle through the safety channel or anexternal channel signaling that it will be transmitting the safetymessages. The cellphone checks its own position with respect to the DSRCdevice and determines that it is within the vehicle and switches off itssafety broadcasts.

In another embodiment, the cellphone device receives its GPS signals andidentifies that it is traveling at a velocity and direction that isbeyond pedestrian speeds and typical pedestrian acceleration patternsand identifies that it is within a vehicle, e.g., a car. It thenswitches the DSRC messaging off or reverts to a very low frequencyupdate.

In another embodiment, the cellphone device receives safety messagesfrom nearby vehicles but observes that a given vehicles position andvelocity is very close to its own position and velocity and identifiesthat it is within that car's confines. The cellphone, in this scenario,switches the DSRC safety message broadcast off.

In another embodiment, the cellphone device broadcasts a request signalwhich is responded to by the vehicle through 802.11 or Bluetooth or acommon communication system. It then performs a ranging operation byrequesting the vehicle to send out audio signals from its speakershelping it identify its position with respect to that car. If thecellphone device identifies that it is within the confines of the car tosome acceptable level of confidence, it switches off its transmissionsof basic safety messages.

In one embodiment, the cellphone device receives a signal from theon-board DSRC device on the vehicle through the safety channel or anexternal channel signaling that it will be transmitting the safetymessages. The cellphone checks its own position with respect to the DSRCdevice and determines that it is within the vehicle and switches off itssafety message broadcasts.

In various embodiments a communications device in system 100 of FIG. 1,and/or communication device 300 of FIG. 3, and/or a communicationsdevice 600 of FIG. 6 and/or one of the communications device of any ofthe Figures includes a module corresponding to each of the individualsteps and/or operations described with regard to any of the Figures inthe present application and/or described in the detailed description ofthe present application. In some embodiments, the modules areimplemented in hardware, e.g., in the form of circuits. Thus, in atleast some embodiments the modules may, and sometimes are implemented inhardware. In other embodiments, the modules may, and sometimes are,implemented as software modules including processor executableinstructions which when executed by the processor of the communicationsdevice cause the device to implement the corresponding step oroperation. In still other embodiments, some or all of the modules areimplemented as a combination of hardware and software.

The techniques of various embodiments may be implemented using software,hardware and/or a combination of software and hardware. Variousembodiments are directed to apparatus, e.g., network nodes, mobile nodessuch as mobile terminals supporting peer to peer communications, accesspoints such as base stations, and/or communications systems. Variousembodiments are also directed to methods, e.g., method of controllingand/or operating network nodes, mobile nodes, access points such as basestations and/or communications systems, e.g., hosts. Various embodimentsare also directed to machine, e.g., computer, readable medium, e.g.,ROM, RAM, CDs, hard discs, etc., which include machine readableinstructions for controlling a machine to implement one or more steps ofa method. The computer readable medium is, e.g., non-transitory computerreadable medium.

It is understood that the specific order or hierarchy of steps in theprocesses disclosed is an example of exemplary approaches. Based upondesign preferences, it is understood that the specific order orhierarchy of steps in the processes may be rearranged while remainingwithin the scope of the present disclosure. The accompanying methodclaims present elements of the various steps in a sample order, and arenot meant to be limited to the specific order or hierarchy presented.

In various embodiments, nodes described herein are implemented using oneor more modules to perform the steps corresponding to one or moremethods, for example, signal processing, signal generation and/ortransmission steps. Thus, in some embodiments various features areimplemented using modules. Such modules may be implemented usingsoftware, hardware or a combination of software and hardware. Many ofthe above described methods or method steps can be implemented usingmachine executable instructions, such as software, included in a machinereadable medium such as a memory device, e.g., RAM, floppy disk, etc. tocontrol a machine, e.g., general purpose computer with or withoutadditional hardware, to implement all or portions of the above describedmethods, e.g., in one or more nodes. Accordingly, among other things,various embodiments are directed to a machine-readable medium, e.g., anon-transitory computer readable medium, including machine executableinstructions for causing a machine, e.g., processor and associatedhardware, to perform one or more of the steps of the above-describedmethod(s). Some embodiments are directed to a device, e.g.,communications node, including a processor configured to implement one,multiple or all of the steps of one or more methods of the invention.

In some embodiments, the processor or processors, e.g., CPUs, of one ormore devices, e.g., communications nodes such as wireless terminals,network nodes, and/or access nodes, are configured to perform the stepsof the methods described as being performed by the communications nodes.The configuration of the processor may be achieved by using one or moremodules, e.g., software modules, to control processor configurationand/or by including hardware in the processor, e.g., hardware modules,to perform the recited steps and/or control processor configuration.Accordingly, some but not all embodiments are directed to a device,e.g., communications node, with a processor which includes a modulecorresponding to each of the steps of the various described methodsperformed by the device in which the processor is included. In some butnot all embodiments a device, e.g., a communications node, includes amodule corresponding to each of the steps of the various describedmethods performed by the device in which the processor is included. Themodules may be implemented using software and/or hardware.

Some embodiments are directed to a computer program product comprising acomputer-readable medium, e.g., a non-transitory computer-readablemedium, comprising code for causing a computer, or multiple computers,to implement various functions, steps, acts and/or operations, e.g. oneor more steps described above. Depending on the embodiment, the computerprogram product can, and sometimes does, include different code for eachstep to be performed. Thus, the computer program product may, andsometimes does, include code for each individual step of a method, e.g.,a method of controlling a communications device or node. The code may bein the form of machine, e.g., computer, executable instructions storedon a computer-readable medium, e.g., a non-transitory computer-readablemedium, such as a RAM (Random Access Memory), ROM (Read Only Memory) orother type of storage device. In addition to being directed to acomputer program product, some embodiments are directed to a processorconfigured to implement one or more of the various functions, steps,acts and/or operations of one or more methods described above.Accordingly, some embodiments are directed to a processor, e.g., CPU,configured to implement some or all of the steps of the methodsdescribed herein. The processor may be for use in, e.g., acommunications device or other device described in the presentapplication.

Various embodiments are well suited to communications systems using apeer to peer signaling protocol. Some embodiments use an OrthogonalFrequency Division Multiplexing (OFDM) based wireless peer to peersignaling protocol, e.g., WiFi signaling protocol or another OFDM basedprotocol.

While described in the context of an OFDM system, at least some of themethods and apparatus of various embodiments are applicable to a widerange of communications systems including many non-OFDM and/ornon-cellular systems.

Numerous additional variations on the methods and apparatus of thevarious embodiments described above will be apparent to those skilled inthe art in view of the above description. Such variations are to beconsidered within the scope. The methods and apparatus may be, and invarious embodiments are, used with Code Division Multiple Access (CDMA),OFDM, and/or various other types of communications techniques which maybe used to provide wireless communications links between communicationsdevices. In some embodiments one or more communications devices areimplemented as access points which establish communications links withmobile nodes using OFDM and/or CDMA and/or may provide connectivity tothe internet or another network via a wired or wireless communicationslink. In various embodiments the mobile nodes are implemented asnotebook computers, personal data assistants (PDAs), or other portabledevices including receiver/transmitter circuits and logic and/orroutines, for implementing the methods.

What is claimed is:
 1. A method of operating a communications device,comprising: generating device location information based on at least oneof a received signal or inertial guidance information; and controllingat least one of a safety message monitoring operation or a safetymessage transmission operation based on the generated device locationinformation.
 2. The method of claim 1, wherein controlling at least oneof a safety message monitoring operation or a safety messagetransmission operation includes: controlling a safety message monitoringperiodicity that determines the time between intervals during whichmonitoring for safety messages is performed or a safety messagetransmission periodicity that determines the time between safety messagetransmissions made by said communications device.
 3. The method of claim2, wherein the safety message monitoring periodicity or the safetymessage transmission periodicity is increased when it is determined thatthe communications device is at a location with higher vehicular trafficthan at another location with lower vehicular traffic.
 4. The method ofclaim 2, wherein the safety message monitoring periodicity or the safetymessage transmission periodicity is controlled as a function ofproximity to vehicular traffic.
 5. The method of claim 1, whereincontrolling at least one of a safety message monitoring operation or asafety message transmission operation based on the generated devicelocation information includes: controlling a transmission power level ofsafety messages transmitted by said communications device.
 6. The methodof claim 1, wherein controlling at least one of a safety messagemonitoring operation or a safety message transmission operation based onthe generated device location information includes: disabling at leastone of safety message transmission or safety message monitoringoperations when said generated device location information indicatesthat said communications device is inside a moving vehicle.
 7. Themethod of claim 6, wherein generating device location information basedon at least one of a received signal or inertial guidance informationincludes: determining if said communications device is located in avehicle.
 8. The method of claim 7, wherein determining if saidcommunications device is located in a vehicle is based on at least oneof: user input; strength and/or rate of safety messages received fromvehicles; a signal received from a safety message system of a vehicle; adetermined rate of motion relative to a rate of motion indicative ofvehicular motion; or a received acoustic signal indicative of saidcommunications device being within a vehicle.
 9. The method of claim 6,wherein controlling at least one of a safety message monitoringoperation or a safety message transmission operation based on thegenerated device location information includes: enabling at least one ofsafety message transmission or safety message monitoring operations whensaid generated device location information indicates that saidcommunications device is outside of a vehicle.
 10. A communicationsdevice, comprising: means for generating device location informationbased on at least one of a received signal or inertial guidanceinformation; and means for controlling at least one of a safety messagemonitoring operation or a safety message transmission operation based onthe generated device location information.
 11. The communications deviceof claim 10, wherein said means for controlling at least one of a safetymessage monitoring operation or transmission operation includes: meansfor controlling a safety message monitoring periodicity that determinesthe time between intervals during which monitoring for safety messagesis performed or a safety message transmission periodicity thatdetermines the time between safety message transmissions made by saidcommunications device.
 12. The communications device of claim 11,wherein said means for controlling a safety message monitoringperiodicity or a safety message transmission periodicity controls thesafety message monitoring periodicity or the safety message transmissionperiodicity to increase when it is determined that the communicationsdevice has moved to a location with higher vehicular traffic fromanother location with lower vehicular traffic.
 13. The communicationsdevice of claim 11, wherein said means for controlling a safety messagemonitoring periodicity or a safety message transmission periodicitycontrols the safety message monitoring periodicity or the safety messagetransmission periodicity as a function of proximity to vehiculartraffic.
 14. The communications device of claim 10, wherein said meansfor controlling at least one of a safety message monitoring operation ora safety message transmission operation based on the generated devicelocation information includes: means for controlling the transmissionpower level of safety messages transmitted by said communicationsdevice.
 15. A computer program product for use in a communicationsdevice, the computer program product comprising: a non-transitorycomputer readable medium comprising: code for causing at least onecomputer to generate device location information based on at least oneof a received signal or inertial guidance information; and code forcausing said at least one computer to control at least one of a safetymessage monitoring operation or safety message transmission operationbased on the generated device location information.
 16. A communicationsdevice comprising: at least one processor configured to: generate devicelocation information based on at least one of a received signal orinertial guidance information; and control at least one of a safetymessage monitoring operation or a safety message transmission operationbased on the generated device location information; and memory coupledto said at least one processor.
 17. The communications device of claim16, said at least one processor is configured to control a safetymessage monitoring periodicity that determines the time betweenintervals during which monitoring for safety messages is performed or asafety message transmission periodicity that determines the time betweensafety message transmissions made by said communications device, as partof being configured to control at least one of a safety messagemonitoring operation or transmission operation.
 18. The communicationsdevice of claim 17, wherein said at least one processor is configured toincrease the safety message monitoring periodicity or the safety messagetransmission when it is determined that the communications device is ata location with higher vehicular traffic than at another location withlower vehicular traffic.
 19. The communications device of claim 18,wherein said at least one processor is configured to control the safetymessage monitoring periodicity or the safety message transmissionperiodicity as a function of proximity to vehicular traffic.
 20. Thecommunications device of claim 16, said at least one processor isconfigured to control the transmission power level of safety messagestransmitted by said communications device, as part of being configuredto control at least one of a safety message monitoring operation or asafety message transmission operation based on the generated devicelocation information.